The carbon rod used as the positive electrode current collector for a manganese dry battery conventionally has a number of fine pores through which air can flow into the battery. In order to check the flow of air, the carbon rod is impregnated with wax. In the case of a high-density carbon rod, it can be impregnated with a small amount of paraffin wax having a low melting point.
Therefore, when an obtained dry battery is stored at e.g. 45° C. for evaluation, it becomes possible to reduce the melting of a sealing agent resulting from eluted paraffin, thereby keeping the sealing performance of the battery in a good condition.
However, streamlining including cost reduction requires the use of a low-density carbon rod, which demands a larger amount of paraffin with which to be impregnated because a low-density carbon rod is highly porous. This increases the amount of paraffin wax to elute during the storage at 45° C., thereby inducing the sealing agent to melt, with the problem of sealing failure.
Therefore, it is an object of the present invention to provide a positive electrode current collector for a manganese dry battery which is freed from the above-mentioned problem and is capable of keeping the sealing performance of the battery in a good condition during high-temperature storage even with a low-density carbon rod.